Steel retainer for rock drills



March 23 1926. 1,577,596

w. A. SMITH STEEL RETAINER FOR ROCK DRILLS v Filed May 20, 1925 IN V EN TOR.

H15 ATTO EY Patented Mar. 23, 192.6.

tJNiTED ST TES PATENT OFFICE.

WILLIAM A. SMITH, OF ATHENS, PENNSYLVANIA, ASSIGNOR TO 'INGERSOLL-RAND NEW JERSEY, A CORTBORATION OF NEW JERSEY.

COMPANY, OF JERSEY CITY,

STEEL RETAINER FOR ROCK DRILLS.

Application filed May 20, 1925.

To all whom it may concern:

Be it known that I, IVILLIAM A. SMITH, a citizen of the United States, and a resident of Athens, in the county of Bradford and State of Pennsylvania, have invented a certain Steel Retainer for Rock Drills, of which the following is a specification accompanied by drawings.

This invention relates to steel retainers for rock drills, of the hammer type, but more particularly to that type of retainer which is pivoted about trunnions carried by the front head of the drill and is provided with a yoke adapted to partly encircle the drill steel.

In many retainers of this type, it is necessary to spread the side arms in order to mount the retainer on the trunnions or supports. Obviously in retainers adapted to be mounted in this manner there are certain limitations as to the design of the yoke, and the size of the material of which the yoke is formed in order that suificient resiliency may be maintained in the yoke for the required spread of the side arms.

It is an object of this invention to enable a steel retainer to be readily mounted on a rock drill and removal therefrom.

Other objects will be in part obvious and in part pointed out hereinafter.

The invention consists of the combination of elements, features of construction and arrangement of parts having the general mode of operation substantially as hereinafter described and more particularly pointed out in the appended claims and illustrated in the accompanying drawings, in which,

Figure 1 is the front end of a rock drill in elevation, showing the yoke in retaininig position,

Figure 2 is a side view in elevation showing the yoke in retaining position,

Figure 3 is a view similar to Figure 1 showing the yoke in releasing position, and

Figure 4 is a perspective view of one of the guide blocks which support the yoke.

Referring to the drawings, the steel re tainer is shown mounted on a rock drill, only a portion of the front of which is shown. In this instance, the front head A is provided with a pair of laterally extending cylindrical trunnions B off-set from the longitudinal axis of the machine. A drill steel C is supported within the front head and is provided with a collar D which coop- Seriai No. 31,506.

crates with a yoke E to prevent ejection of the side arms F.

In order to limit movement of the yoke toward the drill, collars H are forn'ied on the side armsand are adapted to bear against the bottom surface of the guide blocks. The side arms F extend to the rearward of the guide block G and carry springs J for absorbing blows of the drill steel collar 1) against the yoke E. In this instance the end K of each side arm is threaded to receive a nut L and said nut provides a bearing for one end of the spring J.

Suitable means are provided for preventing oscillation of the retainer while the drill is in operation, and to this end shoulders 0 formed on the inner side of the guide blocks G cooperate with a shoulder P near the forward end of the front head to prevent unintentional displacement of the retainer.

Removal of the yoke E from the path of the collar D of the steel may be effected by rocking the retainer about the trunnions B to the position showing in dot and dash lines in Figure 2. In this position, the side arms 'F are spread slightly to permit the shoulders O to pass over the shoulder P of the front head, and the yoke causes the shoulders O to grip the front head firmly until the yoke is again moved to the retaining position by the operator.

In mounting the retainer on the rock drill,

the guide blocks G are arranged on the trunnions B and the side arms F are then on tended through the blocks G whereupon the springs J are placed in position and the nuts L may then be screwed on the ends K of the side arms. The nuts L also serve as a means for regulating the tension of the springs J to suit immediate requirements.

From the foregoing description, it will be observed that the retainer may be readily assembled without the aid of special tools and that any broken or worn parts may be quickly replaced without appreciably decreasing the drilling efficiency of the machine due to delays caused through such replacement.

I claim:

1. In a steel retainer for rock drills, the combination of afront head having cylindrical trunnions, blocks pivoted on said trunnions, a yoke to partly encircle a drill steel, :1 pair of rearward extensions on said yoke slidable through said blocks, a collar on each extension to limit movement of the ixtensions in one direction, springs about said extensions to absorb blows of the drill steel against the yoke and to hold the collars against the block, and means on said blocks to engage the front head for holding the yoke in retaining and releasing; positions.

2. In a steel retainer for rock drills, the combination of a front head having cylindrical trunnions, blocks pivoted on said trunuions, a yoke to partly encircle a drill steel, a pair of rearward extensions on said yoke slidable through said blocks, a collar on each extension to limit mo 'en'ient of the extensions in one direction, springs about said extensions to absorb blows of the drill steel against the yoke and to hold the collars against the block, and a shoulder on each block to cooperate with the front head for holding the yoke in retaining and releasing positions. 4

3. In a steel retainer for rock drills, the combination of a front head having a shoulder near its front end, cylindrical trunnions on'opposite sides of the front head blocks mounted pivotally on the cylindrical trunnions, a yoke to partly encircle a drill steel, a pair of rearward extensions on said yoke slidable through the blocks, collars on the extensions to cooperate with the front ends of the blocks for limiting rearward movement of the yoke, springs on said extensions to absorb blows of the drill steel against the yoke and to hold the collars against the blocks, and shoulders on the blocks to cooperate with the shoulder on the front head for preventing; oscillation of the yoke about the trunnions In testimony whereof I have signed this specification.

IVILLTAh l A. SMITH. 

